Refrigerating apparatus



Dec. 8, 1931. c. E. L. LIPMAN REFRIGERATING APPARATUS Original Filed Ubt. 7, 1927 Patented Dec. 8, 1931 UNITED STATES PATENT OFFICE CARL E. L. LIPMAN, OF BELOIT, MICHIGAN, ASSIGNOR 'IO LIPMAN PATENTS CORPORA- TION, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE s REFRIGERATING APPARATUS Application filed October 7, 1927, Serial No. 224,571. Renewed August 14, 1930.

order that the resistance to starting the compressor again will not be too great. It is necessary, however, not to allow the compressed refrigerant to pass to the low side before it has been cooled in the condenser; otherwise it will warm up the expansion ele-' ment and result in a considerable loss in efficiency. v

The primary object of this invention is to provide a refrigerating apparatus of the above character and a method of operating the same in which the pressure in the high side is dropped considerably when the compressor is stopped without allowing the compressed refrigerant to warm up the expansion element.

Another important object of this invention is to provide a system in which the pressures on the high and low sides are allowed to substantially equalize, thereby reducing the effective pressure on the high side when the compressor stops and is built up again gradually when the compressor starts so that the starting torque is reduced to a minimum.

A further object of this invention is to provide an apparatus of the above type characterized by the foregoing provisions which is simple and efficient and which is particularly adapted for household use.

Other and further objects of this invention will be apparent as the-same becomes better understood from an examination of the specification and claims in connection with the accompanying drawings, wherein:

Figure 1 is a plan view of an apparatus embodying this invention, and

Figure 2 is an elevational View of the same.

Referring to the drawings more particularly, there is shown a refrigerating apparatus of the general type described in connection with my copending application, Serial No. 92,704, filed March6, 1926, for refrigerating apparatus. As in said copending application, the apparatus chosen to illustratefthe principles of this invention is of the household type and is mounted upon a rectangular mount 3 which is adapted to be removably connected with a refrigeratin cabinet in the same manner as the removablemount in said application.

The high pressure side of the apparatus is mounted on top of the member 3 and the low pressure side is mounted on the bottom of the said member, the two sides in practice being normally insulated from each other in order that the heat from the high side may not be imparted to the low side.

The high side consists of a motor compressor unit 4 mounted on top of the mount 3, a condenser 5 to which the compressor is adapted to deliver compressed refrigerant, and a cooling fan 6 driven by a motor 7 for cooling the condenser and motor compressor.

The low side comprises an evaporating element 8 which may be of such construction as to provide for the support of ice trays (not shown) for making ice, as well as for coolmg the refrigeration compartment (not shown). The evaporating element 8 s provided'withan expansion device 9 which'may be either an expansion valve or a float chamher and a float valve, and is adapted to receive refrigerant which has been cooled in the condenser and expand it to produce the desired cooling effect in the element 8. The refrigerant, after it has expanded in the evaporating elements and has done its work,

is withdrawn through a pipe 11 and a check valve 12 to a storage tank 13 which is in communication with the intake of the compressor by means of a pipe 14. i

In operation, the compressor, which in this instance is driven by, a single phase split phase motor, is adapted to withdraw refrigerant from the tank 13 in the form of gas, compress the same and deliver the compressed refrigerant to the condenser 5 where it is cooled and liquefied by the fan 6. The cooled liquid refrigerant s delivered to the 'evaporating element 8 through the expansion device 9 and after it has produced the necessary cooling effect in said element, it is withdrawn in the form of gas through the check 12 back to the storage tank 13. Whenever the com pressor is stopped, the high pressure of the refrigerant in the condenser will drop by reason of the refrigerant slipping back through the rotary compressor to the tank 13 and the pressure will become equalized on both sides of the compressor at a considerably lower pressure. Thetank 13 is of sufficient capacity to allow enough refrigerant to slip back in this manner to cause'a considerable drop in pressure in the condenser and to provide a sufficient supply of refrigerant to enable the pressure in the condenser to be built up again gradually.

The presence of the check valve 12 between the tank 13 and the evaporating element 8 prevents the refrigerant from leaking back beyond the tank 13 into the evaporating element. The warm refrigerant from the high side cannot therefore enter the expansion element to raise the temperature thereof and thus reduce the efficiency of the system.

hen the compressor is again started up, the pressure in the condenser, having dropped considerably, does not present too great a. resistance to the starting of the compressor and since a comparatively large quantity of gas is contained in the tank 13 at the same pressure as is in the condenser, on the intake side of the compressor,the pressure in the condenser may be built up gradually. By such an arrangement whereby the pressure in the condenser is allowed to build up gradually, a minimum of resistance to the starting of the compressor is obtained, permitting an ordinary single phase split phase motor to be used for operating the compressor.

It will be apparent that the foregoing arrangement is particularly adapted for household use in that it reduces the requirements of the motor and permits the simplest form of motor to be used.

I am aware that many changes may be made without departing from the principles of this invention and therefore do not wish to be limited to the details shown or described.

I claim:

1. In a refrigerating system, the combination of a rotary compressor, a high pressure side connected to the compressor for receiving compressed refrigerant therefrom, a low pressure device for receiving refrigerant from the high side, and means in circuit between saiddevice and compressor for storing refrigerant of such quantity that when the compressor stops, the refrigerant may slip back through the rotary compressor to said means causing a considerable drop inpressure in the high side without permitting any ofthe refrigerant which has slipped back to enter the low pressure device.

2. In a refrigerating system, the combination of a compressor, a high pressure side connected to the compressor for receiving compressed refrigerant therefrom, a low pressure device for receiving refrigerant from the high side, and means for storing refrigerant of suchquantity that when the compressor stops the refrigerant may slip back through the compressor to said means causing a considerable drop in pressure in the high side without permitting any of the refrigerant which has slipped back to enter. the low pressure device.

3. In a hermetically sealed refrigerating system, the combination of a hermetically sealed motor compressor unit, a condenser for receiving the compressed refrigerant, an evaporating element into which the refrigerant is delivered from the condenser, a connection between said evaporating element and said compressor adapted to receive leakage refrigerant past the compressor and permit substantial equalization of the refrigerant pressure on both sides of the compressor when the compressor is idle to reduce the starting load upon the motor, and means in said connection for preventing entry of said leakage refrigerant into said evaporator.

,4. The method of easing the starting of a compressor in a hermetically sealed refrigerating system including a condenser and an evaporator which consists in providing storage to accommodate the refrigerant medium leaking past the compressor when idle in sufficient quantities to enable the compressor to start without load and preventing said leak refrigerant medium from entering the evaporator.

In witness of the foregoing I affix my signature.

CARL E. L. LIPMAN. 

